BUILD A DIY SOLAR PV/THERMAL SYSTEM

​PV/T systems maximise energy production in a smaller area when compared to individually installed solar pv and thermal systems, by utilising the typically considered 'waste heat' generated by the pv cells. Currently, the best pv cells available have an efficiency between 20-22%. That means only ~20% of the solar energy hitting the cells is converted to electricity, while the rest is either reflected or absorbed as heat and in most cases lost to the outdoor environment. Introducing a fluid within an enclosed pv array will remove and transfer this heat from the cells to be used for direct space heating or DHW.

The ratio of heat to electricity produced from the system detailed below is approximately 7 to 1, meaning that on reasonably sunny days the cells will absorb and release 7 times more heat energy than what they will produce in electricity. This also means that if the pv array were simply conventional panels installed on a rack or roof and exposed to the outside environment, then up to 85% of it's true potential would be wasted.

​This system is designed for both direct space (air) heating and water heating, the latter serving as a 'dump' or diversion to DHW storage when direct space heating isn't required. Because this is a 'covered' PV/T array, there must always be an airflow through the collector during sunny weather because the idle temperature inside can rise well above 110°C and damage the encapsulating material. But with the high efficiency Sensda fans rated for 30W/h power consumption, the trade off is highly beneficial. During summer months the heat generated is used strictly for DHW, and excess is dumped outside while circulating cooler fresh air into the living space at the same time, so this system will be functional all year to maximise ROI (return on investment).

If you're interested in this project, check out the video series below. A step by step PDF guide will be available soon, which includes a material list, detailed instructions w/ graphics, and plans/wiring schematics. An editable 3D CAD will also be included (Google Sketchup is required to view/edit the CAD). This system was designed using very basic materials (some even recycled) to help keep the construction costs low, so there's lots of room for innovation.